The present invention is directed to a single-face station for a machine which produces corrugated cardboard sheets, which machine includes a frame which has a stand with two lateral wall members between which are installed a lower pressure roll and an upper cassette that carries a pair of superimposed corrugating rolls.
The single-face station is usually located upstream of a machine that produces corrugated cardboard. In such a station, a first web of paper is corrugated when travelling between an upper corrugating roll and a lower corrugating roll. A glue application roll is located almost at the level of the lower corrugating roll and will apply the glue on the crest of the corrugated sheet prior to the application of a second covering sheet, such as paper, by means of the pressure roll located under the lower corrugating roll.
On most of the current machines of small and medium dimensions, the rolls are simply arranged on bearings that are permanently fixed or mounted in the frame of the station. However, it is also sometimes necessary to take out the corrugating rolls for maintenance and repair. It is also useful to have the possibility of taking out the same rolls to exchange them in order to modify the flute profile and adapt it at best with regard to the flute required for the corrugated board to be produced. However, the dismantling operation for the corrugating rolls arranged on bearings that are permanently fixed is difficult and time-consuming because it requires a tilting of the massive upper crossbar around a lower hinge in order to obtain access to these rolls and to their bearings. It also involves uncoupling of the various connections of the drive motors and of the ducts delivering steam to the corrugating rolls, and then the undoing of the anchoring points of the bearings in order to take out the rolls to be exchanged and to bring the next rolls to their operating position.
In consideration of the above-mentioned difficulties, cassettes for carrying the pair of corrugating rolls with their bearings and drive motors have now been manufactured for machines of larger dimensions. These cassettes can be taken out laterally when rolled on rails permanently fixed on the frame, as well as onto rails belonging to a carriage. It is also known for a particularly large-dimensioned machine in which the cassette can be fitted in an upper space of the frame in order to lower a second cassette according to an orthogonal direction, which action then allows a very quick exchange of the corrugating rolls and, hence, a change of the flute profile. Every cassette can also be taken out laterally for the exchange of the corrugating rolls or for their maintenance.
However, up to now, this cassette system has only been applicable to machines with massive frames. In fact, the large dimensions of the cassettes and the importance of the forces, that are applied to the frame, have required an overdimensioning of the framework making up the lateral wall members of the frame.